Carburetor



April 12, 1932 J. scHwElss ET AL 1,853,287'A CARBURETOR Filed Feb. 23,1929 n' Patented Apr. 12, 1932 I UNITED .STATES PArEuroFFl-ca JOSEPHSCHWEISS AND GEORGE R. ERIOSON, OF ST. LOUIS, MISSOURI, ASSIGNORS TOCARTER CARBURETOR CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION oFDEAWABE This invention relates to carburetors and particularly todevices for producing a temporary enrichment Aof the mixture delivered'p when the throttle is opened. The jet throiljgh which this pumpdischarges is entirely separate and distinct from the main fuel supplymeans of the carburetor. The arrangement serves not only as a'means oftemporarily env riching the mixture upon acceleration of the engine, butas a means of priming the engine before start-ing.

During operation, when the temperature is low, it is desirable to squirtthe additional fuel high into the air stream so that a large `part of itwill be vaporized by the contact with the air, and to secure the mostperfect vaporization,the jet is directed so that the larger drops willimpinge on the hotspot or other warm portions of the intake manifold, sothat they will be vaporized by the heat thereof. v As the temperaturerises, it becomes less desirable to squirt the supplementary jet intothe air stream and onto the surface of the intake manifold, and undercertain conditions serious interference with the operation of the motormay result fromsuch an arrangement. L A It is an object of thisinvention to provide means to deflect the `jet'of fuel delivered by theaccelerating pump at high temperatures in such a manner that it will notbe directed into the most rapidly moving part of the air e stream and-Will not impinge on the hot sur- 40- faces of the manifold.

Another object of the invention .is to provide means automaticallyoperable at high temperatures to prevent the over-enrichment of the fuelmixture by the accelerating pump lwithoutk in any way affecting theoperation of the pump itself.

It is another object of the invention to providey means automaticallyoperable at high temperatures to distribute the charge of fuel @odelivered bythe accelerating pump over a i CARBURETOR applicati@mearebruary 23.11929. serial 1v.k 342,060.

longer period whereby the over-enrichment .of the mixture is preventedand the temporary increase of power is prolonged. Other objects willappearfrom the following description and the accompanying drawings,

referring to which:

Figure 1 is a somewhat diagrammatic cross sectional view of a carburetorembodying our inventionsl Figure 2 is a side elevation of the carburetorshown in Figure 1.

Figure 3 is a side view of one form of thermally operated deflector.

Figure 4 is an end view'of the delector shown in Figure 2.

The reference numeral 1 designates a main body member having apassageway 2 ter'- minating in a flange 3 which is adapted to be securedto the intake manifold of an internal combustion engine, the manifoldbeing indicated at 4:V A butterfly valve 5 of convene tionalconstruction` is mounted on a shaft 6v and serves tol control he flow ofmixture through the passageway 2. A suitable lever 7 4is provided foroperating the` throttle shaft. Also mounted. on the shaft 6 -is a crank8 which is pivoted at 9`to the oscillating piston 1() ofthe acceleratingpump 11.

The carburetor is supphed with air from the usual air horn 12. Thechamber 13 provides a passage for the airto the throat of the venturi 14and into the`mixing chamber 15A where it is mixed with fuel beforepassing through the throttle Vvalve and the outlet conduit 2. The fuelis supplied by conventional means through the inlet nipple 16, which issecured to the body member l and communicates with the inlet side of thefloat valve 17, the movement of this valve being controlled in a wellknown manner by the oat 19 which is carried inthe float chamber 18. Whenthe fuellevel .in the fuel bowl or lt will be seen that the fuel levelA-A is y such as to normally 'maintain a quantity of fuel in thedepression 0r accelerating well 40 at the lower part of the chamber 13.This fuel accumulates in the accelerating well during low speedoperation and is picked up by an increase in the speed of the airstream, such would occur when the throttle is suddenly opened, therebygiving an additional quantity of fuel for acceleration.

The tube 20 is connected to the fioat chamber at a point below the fuellevel to provide a main fuel supply. The accelerating pump 11communicates with the conduit 21, the inlet valve 22, and the outletpassage 23; an inwardly opening check valve 24 is seated against-theinlet`22, as shown, thus forming an inlet check valve for the pump. Thepassage 23 is provided with a shoulder 25 upon which is seated a ballcheck 26 forming an outlet check valve for the pump. A suitable jetnozzle 27 is secured to the upper end of the bore 23 and serves toretain the ball check 26 in position as well as to form the dischargenozzle for the accelerating pump.

The body of the carburetor is provided with a bore 28 to receive asubstantially cylindrical plug 29, and a set screw 30 is provided toreleasably hold the plug 29 in4 position. The upper end of the plug isprovided with a screw driver slot 31 which serves to adjust the plug andto indicate its position. The inner and opposite end of the plug isslotted to receive a strip of bimetallic thermally responsive metal 32which extends downwardly and toward the line of discharge D of thel jet27. Upturned lugs or baliles 33 are attached to the strip 32 and arepreferably formed in the manner shown to a diameter not greater thanvthat vof the bore 28 so that they can be readily withdrawn or insertedwith the strip through the bore 28.. The lugs are attached to thethermostatic strlpxlpy a rivet at the lower end only, so that the ndingof the strip under the infiuence of temperature changes will not beinterfered with by the stiffness of the flanges.

The strip 32 com rises a strip of metal 34 having a.- low coe cient ofexpansion attached to another strip of metal 35 having a highcoefficientof expansion.

The operation of the device is as follows:

' When the carburetor is in operation, suction in the manifold 4 drawsair through the turi 14. The reduction of pressure at the throat of theventuri draws fuel from the` tube 20 and causes it t-o be sprayed intothe mixing chamber 15. The throttle 5 controls the passage of mixturefrom the mixing chamber into the manifold. When the throttle valve ismoved toward closed position, the piston 10 is moved upwardly in the Piliary fuel through said nozzle upon a movepump 11, drawing fuel throughthe inlet 22 past the ball check 24 and` into the pump.

When it is desired to accelerate the engine,

the throttle is opened causin the crank 8 tovpicked up by the air passinthe walls of the conduit is vaporized morev slowly-and is eventuallypicked up bythe air stream and carried into the engine. A

As the temperature rises, the drops of fuel which impinge on the wallsof the passageway are vaporized more quickly, resulting in a suddenover-enrichment of the mixture .i

upon operation of the' pum and insufficient duration of time duringwhich the additional fuel is supplied. Under these conditions, theincreased temperature bends the strip 32 to the left, as shown in Figure1, and intercepts a portion or all of the jet, causin the fuel to bedeflected against the wall o the chamber 13 below the venturi.

The rate of flow of air in this part of the carburetor is lower than therate of flow through the venturi, the outlet passage 5, and the intakemanifold 4; and for this reason the deflected fuel is vaporized moreslowly than if it had been squirted ydirectly through the throat of theventuri and the most rapidly moving partof the air stream onto the warmvsurfaces over which air is passing at a relatively high speed.

The fuel will, however, eventually be through the chamber 13 and carriedinto t e engine. `It is also quite likely that the walls of the chamber13 will be cooler than the walls of the conduit 2 and the intakemanifold 4, and for this reason also the slower vaporization will occur.B this arangement, the interval durin plied 1s lengthened while thetemporary supply of over-rich mixture is avoided.

It will be seen that we have provided a simple, reliable, and easilymanufactured device for. the purpose described, and that the w ich theenriched mixture is supinvention may be embodied in various ways.

Accordingly, we do not wish to be limited, exce t as set forth in thefollowing claims.

e., claim:

-1. In a carburetor, a mixin conduit, a main fuel supplly tube connectelto said conduit to norma `y supply fuel thereto, a valve forcontrolling the passage of mixture through said conduit, an auxiliaryfuel supl'y nozzle, means for discharging a jet of auxment of saidthrottle, a baille, and thermally operable means to move said bale intothe path of said jet when temperature rises.

2, In a carburetor, a mixing conduit, an

accelerating pump adapted to discharge a jet of fuel into said conduit,a baille normally out of the path of said jet, and thermally operatedmeans for moving said baille into the discharge jet of said pump whenthe temperature is high. 1

3. In a carburetor, a mixing conduit, an accelerating pump having adischarge jet directed toward the most restricted part of said conduit,and automatic means operable upon an increase in temperature fordeflecting said jet into a less restricted part of said conduit.

' by temperature changes to deflect said dis- 4. In a carburetor, amixing conduit adapted toV convey an air stream, an accelerating pumphaving a discharge jet arranged to discharge fuel into a rapidly movingpart of said air stream, and means operable at high tempera-ture todeflect said jet into a slower moving part of said air stream.

5. In a carburetor, a mixing conduit adapted to convey an air stream, apump having a discharge jet/arranged to'discharge fuel into a certainpart of said conduit, and automatic means operated by temperaturechanges to cause said fuel to be discharged into a diiferent part ofsaid conduit.

6. In a carburetor, means forming a main conduit, an accelerating wellin the lower portion of said conduit, an accelerating pump adapted todischarge into said conduit above said accelerating Well, and meansoperated charge into said accelerating well.

7 In a carburetor, a mixture conduit, a fuel chamber, a main fuel supplymeans normally supplying fuel from said chamber to said conduit, a pumpfor supplying additional quantities of fuel to a certain part of saidconduit, and thermally-operated means for deflecting the additional.quantities of fuel to another part of said conduit when the temperatureis high.

'8. In a carburetor, a fuel chamber, a mixture conduit, means normallysupplying fuel from said fuel chamber to said mixture con- I trollingsaid valve, means operated by said controlling means for supplyingadd1tional quantities of fuel to a part of said conduit, and adelectoroperable at 1.high temperatures 'to deflect the additional fuelto another part of said conduit.

9. In a carburetor, a body member having a-chamber therein, apassageway' forming an outlet for said chamber, a manually operablevalve controlling said passageway, a pump, a discharge nozzle for saidpump mounted in the wall of said chamber, means for simultaneouslyoperating said pump and said valve, and a thermally operated baffle insaid chamber.

from in a substantially axial directiorf, a baffle member carried bysaid strip and attached thereto only at a point near theend of the stripopposite the plug, vwhereby flexing of said strip will not beinterfered-with by the stiffness of ysaid baille member. n

v11.'In a device of theclass described, a substantially cylindricalplug, a birnetallic strip attached to an end of said plug and extendingin an axial direction therefrom, a flanged baflle carried by said strip,said plug, flange, and strip being insertable through a circular openingof the same diameter as said plug.

12. In a device of the class described, a substantially cylindricalplug, a bimetallic. strip attached to an end of said plug and ex--tending in an axial direction therefrom, a

flanged baille carried by said strip, said plug, flange, and strip beinginsertable ina circular opening of the same diameter as said plug and aneccentric screwdriver slot in the end of said plug opposite said stripfor receiving an adjusting tool and for indicating the position kof saidbaille.

13. In a device of the class described, a conduit, means forming aconduit, a manually operable priming pump for dischargving a jet of fuelinto said conduit, a baffle adapted to be moved into or out of the-pathof said jet, and thermostatic means for moving said baille. '1

' 14. In a carburetor, means forming a mixing conduit and a constantlevel fuel supply chamber, a main fuel nozzle discharging fuel 100 fromsaid constant level supply chamber into said mixing conduit, a pumphaving a fuel inlet from said constant level supply chamber, a checkvalve for controlling-said inlet said.. pump having a discharge nozzlefor discharging fuel into said mixing conduit and heat controlled meansfor returning a portion of the fuel dischargedby saidpump towards saidconstant level supply chamber.

In testimony whereof we aix our signatures this 14th day of February,1929.

. JOSEPH SCHWEISS.

GEORGE R. ERICSON.

10. In a device of the class described, a cylindrical plug, a bimetallicstrip secured at p one end of said plug and extending there-

